Support flange having electrical contacts to provide electrical continuity upon spindle motor mounting to base

ABSTRACT

Spindle motor electrical- and motor-to-base interfaces. A compliant connector along with a circuit on a support flange is provided below a stator assembly for providing: An insertable spindle motor to drive base with less specific orientation. The support flange may comprise a small printed circuit cable or a printed circuit board. Additionally, non-specific orientation of a spindle motor to drive base assembly is described using circular traces oriented about a support flange. A circular connector is also described, as well as a biased support flange.

TECHNICAL FIELD

The present invention generally relates to assembly and manufacture ofdisc drives. The present invention is directed to spindle motor-to-baseassembly for hard disc drives. In particular, the present invention isdirected to winding termination, electrical interface, and mechanicalinterface of a spindle motor.

BACKGROUND ART

A hard disc drive typically comprises one or more discs connected to aspindle ("rotor") driven by a motor ("spindle motor"). The spindle motoris for providing angular velocity to the discs ("disc pack") attached tothe rotor. Read/write heads are positioned relative to the discs("platters") for storing and/or retrieving information.

To mitigate problems due to contamination, the hard disc drive is sealedin a housing. This "sealed" volume of the hard disc drive, referred toas a drive volume, is bounded on one side by a drive base.

Electrical components disposed on a printed circuit board (PCB) known asa driver board are coupled to the spindle motor by way of electricalconnections. The driver board is typically located external to the drivevolume, so that the electrical connections must lead into and out of thedrive volume.

In rotating shaft spindle motors, a rotor shaft rotates with a rotor hubor cup. In the past, this configuration presented many problems for themanufacture of hard disc drives. To alleviate some of the problemsassociated with rotating shaft motors, it would be desirable to provide:

1. A spindle motor assembly process which relieves tight tolerancesassociated with end turns of the motor.

2. A spindle motor assembly process where electrical interfaceconnections do not interfere with motor operation.

3. A spindle motor-to-base assembly process with less specific ornon-specific orientation of the spindle motor to the base.

4. A spindle motor assembly process which requires less manual labor.

5. A spindle motor assembly process which reduces costs associated withthe printed circuit cable (PCC), including part purchase, assembly,damage and rework costs.

A stationary shaft motor configuration (not shown) is a motor in whichthe rotor shaft does not rotate with and as part of the rotor. Some ofthe problems associated with rotating shaft motors have been addressedin stationary shaft motor designs. Such stationary shaft motor designsinclude:

1. Installation of a PCC to a base prior to mounting a motor. In thisapproach, electrical contact between the motor and the PCC occurs withphysical assembly. This approach is hereinafter referred to as "approachone."

2. Potting of a PCB into a stator inner diameter. In this approach, anelastomeric connector is electrically connected to the PCB. Theconnector, mounted through the base, is in contact with driver boardpads. This approach is hereinafter referred to as "approach two."

3. Assembling a motor in a base. In this approach, a PCB is mounted tothe base. An elastomeric connector is mounted through the base to driverboard pads. This approach is hereinafter referred to as "approachthree."

All of these stationary shaft motor applications include compliantconnectors, mitigate end turn sizing problems, and reduce PCC costs.Approaches two and three provide a circuit between the motor and driverboard upon mechanical contact. Approach one utilizes a stationary shaftin-hub motor. In approach one, discs are installed onto a spindle priorto motor-to- base assembly.

DISCLOSURE OF INVENTION

In accordance with the present invention, there is provided a hard discdrive having a drive base, a spindle motor, and a driver board, andhaving improved spindle motor-to-base electrical and mechanicalinterfaces. This is accomplished by use of a flange that includes acircuit. By the term circuit is meant a path providing electricalcontinuity between two points. The flange and circuit are attached toand located under the spindle motor. The circuit includes contactsurfaces for electrical continuity between stator windings of thespindle motor and contacts of a connector mounted in the base. Theconnector, mounted in and extending through the base, is located underthe spindle motor. Connector contacts may then be connected to a driverboard or other circuitry means for driving the spindle motor.

The flange is attached to the outer diameter of a stator sleeve ordirectly to a stator assembly, e.g., the lower periphery of statorwindings ("end turns"). This attachment may be made by any suitablemethod such as bonding, staking, or the like. Bonding the flange to endturns may result in less deflection of the circuit, and may improve endturn sizing requirements.

The flange and circuit may be made as one integral PCB or as separatecomponents, such as a plastic disc and a PCC. The flange may also bemade as a molded part, if desired. If the flange is molded, the circuitmay be plated and then etched on the flange, or the flange may be platedwith a pattern for forming the circuit. In the case of plating a patternonto the molded flange, the step of etching is avoided. Alternatively,the conductive elements which form the circuit may be located in place,and then a plastic or other suitable material is poured around theconductive elements to form an "overmolded" flange. With an overmoldedor molded flange, tighter tolerances on interface dimensions arepossible. Accordingly, a molded or overmolded flange may be attached tothe outer diameter of a stator sleeve by means of a press fit. In thecase of a press fit, a tolerance ring may be used for flange-to-statorsleeve assembly. Moreover, the flange may be biased in its attachment tothe outer diameter of the stator sleeve for improving and maintainingelectrical contact.

The circuit may comprise traces or pads or a combination thereof.Electrical contact between the traces and pads may be either through oraround the thickness of the flange. The pads may be disposed on thetopside of the flange and the traces on the bottom side of the flange.This allows for specific orientation of the motor to the flange, andless specific or non-specific orientation of the flange to theconnector. Alternatively, pads may be disposed on both the underside andthe topside of the flange for specific orientation to both motor andconnector. Or, traces may be disposed on both underside and topside ofthe flange for less specific or non-specific orientation to both motorand connector.

By non-specific orientation, it is meant that connector contact may beoriented anywhere about 360 degrees with respect to the spindle motor.Non-specific orientation may be facilitated with circular traces. Byless specific orientation, it is meant that connector contact may beachieved within a predetermined angular range, but at orientationsoutside such a range, electrical contact cannot be provided. Thus, lessspecific orientation may be provided with traces having the shape ofarcuate segments.

In accordance with the present invention, a connector is located throughand in a drive base under a portion of a support flange in nearproximity to a mounting location of a spindle motor. By mechanicalcontact due to assembly, conductive elements of the connector are put inelectrical continuity with the circuit. Thus, mechanical contact owingto assembly of the spindle motor-to-base may be used to provideelectrical continuity into and out of a drive volume in accordance withthe present invention.

The conductive elements of the connector may include button contacts,elastomeric conductive elements, or springs. However, other connectorconductive elements may be used in accordance with the presentinvention. Notably, button contacts are preferred due to lowercompression forces needed, as compared to elastomeric conductiveelements, for maintaining electrical contact.

In accordance with the present invention, The connector may be made as acylindrical connector. The cylindrical connector allows the drive volumeto be sealed with a press (interference) fit, as opposed to applying aseparate seal or sealing with adhesives. Optionally, adhesive may beused with the cylindrical connector to seal the drive volume.

Assembly of a hard disc drive in accordance with the present inventiondoes not require extensive routing of a PCC, which significantly reducesassembly costs. When applying the principles of the present invention torotating shaft motors, discs may be installed onto a spindle motor priorto installation of the spindle motor to the drive base and rotation ofthe hub cannot contact the circuit. Less specific and/or non-specificorientation facilitates this assembly process. For additional ease ofassembly, solder pads may be disposed outside an outer diameter ofstator laminations. This allows easier access to solder lead wires fromthe stator windings to the solder pads on the topside of the flange.Moreover, soldering may then be accomplished manually or in automatedfashion.

While reduced labor assembly costs follow from the present invention, itis important to note that part costs, owing to a shorter PCC, may alsobe reduced. Also, importantly, PCBs and plated circuits may be lessexpensive than PCCs. Thus, for example, the ability to use a PCB insteadof a PCC is a possible cost reduction.

End turn sizing is reduced or eliminated with the present invention.With the present invention, there is less criticality in the lengthwiseouter dimension of stator windings. Thus, a standard winding for astator assembly will result in usable product without continuousmeasurement and adjustment therefor.

In the preferred embodiment of the present invention, the flange isbonded to end turns of the stator assembly. Furthermore, the flangeaccording to the present invention may be made to have an outer diametersmaller than the rotor inner diameter. This will further ensure nointerference between the flange and operation of the spindle motorrotor.

Other features of the present invention are disclosed or apparent in thesection entitled: "BEST MODE FOR CARRYING OUT THE INVENTION."

BRIEF DESCRIPTION OF DRAWINGS

For fuller understanding of the present invention, reference is made tothe accompanying drawing in the following detailed description of theBest Mode of Carrying Out the Invention. In the drawings:

FIG. 1 is a cross-section of a portion of a prior art hard disc drivevolume using an extensive PCC;

FIG. 2 is a top view of the prior art PCC of FIG. 1;

FIG. 3 is a cross-section of an enlarged portion of the hard disc drivevolume of FIG. 1;

FIG. 4 is a cross-section of a portion of a hard disc drive of apreferred embodiment of the present invention;

FIG. 5 is a top exposed view of the motor assembly of FIG. 4;

FIG. 6 is a cross-section of a portion of a first alternate embodimentof a hard disc drive in accordance with the present invention;

FIG. 7 is a perspective view of an elastomeric type connector of theprior art;

FIG. 8 is a cross-section of a portion of a second alternate embodimentof a hard disc drive in accordance with the present invention;

FIG. 9 is a top exposed view, partly broken away, of the motor flangeassembly of FIG. 8;

FIG. 10 shows patterns for circuit traces and pads which may be used ona top and/or bottom surface of a flange in accordance with the presentinvention;

FIG. 11 is a cross-section of a portion of a third alternate embodimentof a hard disc drive in accordance with the present invention;

FIG. 12 is a top view of a PCC in accordance with the present invention;

FIGS. 13-19 are cross-sectional views of portions of alternativefeatures for a hard disc drive in accordance with the present invention;

FIG. 20 is a plan view of a PCB flange for a cylindrical connectorconnection in accordance with the present invention;

FIG. 21 is a cross-sectional view of a portion of a hard disc drivehaving a cylindrical connector in accordance with the present invention;

FIG. 22 is a perspective view of a cylindrical connector in accordancewith the present invention; and

FIGS. 23 and 24 are side views of a biased flange in accordance with thepresent invention.

Reference numbers refer to the same or equivalent parts of the presentinvention throughout the several figures of the drawing.

BEST MODE FOR CARRYING OUT THE PRESENT INVENTION

In accordance with the present invention, several embodiments areprovided for electrical coupling of motor windings to driver circuitryexternal to a hard disc drive volume. After review of the severalembodiments, it should be understood that a flange having printedcircuits (a "circuited flange") may be attached to a motor. The motormay be of a stationary or rotating shaft configuration. The circuitedflange may be attached to stator end turns or the outer diameter of astator sleeve. This combination of motor and circuited flange may thenbe attached to a connector assembled through a base casting. Assembly ofthe two portions (motor and circuited flange, and connector and base)may be accomplished with specific, less specific, or non-specificorientation as described above.

Background

Prior to a discussion of the embodiments of the present invention, amore detailed understanding of the background art of rotating shaftmotors is appropriate. A prior art rotating shaft motor for a hard discdrive is shown in FIG. 1. As shown, a PCC 103 is routed under a disc 110and through an area containing a voice coil motor (not shown) and anE-block (not shown) to a connector 108. An interconnect system 109 isprovided for electrically connecting connector 108 to the driver PCB 107through a base casting 106.

Referring to FIG. 3 taken in conjunction with FIG. 1, an enlarged viewof area 111 is provided. As shown, hold-down clip 102 and machine screw101 are used to attach PCC 103 to base 106. Solder pads 100 are locatedwithin the outer diameter 104 of stator teeth for connection to coils105 with wires (not shown).

Referring now to FIG. 2 with continuing reference to FIG. 3, PCC 103 isshown. Spindle motor 113 is located through hole 114 provided in the PCC103. PCC 103 is routed under disc 110 and fastened to base 106. Screw101 is located through hole 112 for fastening PCC 103 to base 106. PCC103 is routed under motor hub 115, up ramp 116, under disc 110, aroundthe actuator cartridge (not shown), and folded over interconnect system109 (shown in FIG. 1). PCC 103 is then tacked down with adhesive,machine screw 101, and clip 102 to base casting 106 to preventinterference with operation of spindle motor 113. PCC 103 is connectedto connector 108 (shown in FIG. 1) with end 117 for electrical couplingwith interconnect system 109 (shown in FIG. 1).

Due to tolerance limitations between hub 115 and base 106, PCC 103 hadto be precisely located axially to avoid interference with operation ofspindle motor 113. Therefore, as coils 105 were created by wrapping wirearound a stator laminated core, end turns, arising therefrom, had to becompacted. A tight tolerance on end turn sizing resulted to ensure PCC103 did not interfere with operation of rotor 118 and with mounting ofspindle motor 113 to base 106.

In the past, PCC 103 was very costly to make and install. The greatdistance over which the PCC 103 travels increases assembly cost of thespindle motor 113 to the base 106. Also, PCC 103 had to be preciselylocated and attached to base 106 to avoid interfering with operation ofrotor 118.

Still another problem with the PCC used heretofore is the specificorientation requirements with respect to the spindle motor 113. Asshown, solder pads 100 are carefully located to register with thestators of spindle motor 113. Therefore, spindle motor 113 and PCC 103had to be oriented to one another in a specific manner.

Preferred Embodiment

The present invention provides a spindle motor having a PCB made intothe form of a disc. The stator windings are attached on one side of thePCB (the PCB is attached to stator end turns), and the other side of thePCB has exposed circular traces.

A connector which mechanically conforms to mating contours forconnection (a "compliant connector") is disposed for contact with theexposed circular traces. As the compliant connector is mounted throughand in the base casting near the motor mount, the spindle motor and PCBmay be assembled to the base casting causing the exposed traces to makecontact with electrical contacts of the connector. Thus, the spindlemotor is in electrical contact with the connector. The opposite side ofthe connector is attached to the driver board (drive circuitry), whichis located below the base, external to the drive volume.

As disc drive assemblies are well known in the art, in order to avoidconfusion while enabling those skilled in the art to practice thepresent invention, this specification omits many details with respect tothe disc drive assembly.

Referring to FIG. 4, there is shown a cross-section of a preferredembodiment of a portion of hard disc drive assembly 26 in accordancewith the present invention. Spindle motor assembly 92 is a rotatingshaft motor, as opposed to a stationary shaft motor.

In the preferred embodiment, connector 43P is a cylindrical, compliantconnector. Connector 43P extends through base 15 in near proximity towhere spindle motor assembly 92 is mounted to base 15. Connector 43P maybe sealed to drive base 15 with adhesive. Button contacts 44 areemployed in housing 13 of connector 43P along with conductors 261 andscrew 68. Screw 68 is to ensure reliable contact between connector 43Pand PCB driver board 11. Connector 43P electrically couples spindlemotor assembly 92 to driver board 11.

Support flange 12 is attached to stator assembly 20 with adhesive 119.Adhesive 119 may be used to fill any gap resulting between statorassembly 20 and support flange 12. Alternatively, flange 12 may beattached to outer diameter 16A of stator sleeve 16 with adhesive 119,and thus flange 12 need not be bonded to stator windings.

Rotor 18 is mounted on spindle bearing 22 of spindle motor assembly 92.Attached to rotor 18 is magnetic assembly 17. As is known, magneticassembly 17 may comprise a permanent magnet. Stator assembly 20 isfitted to stator sleeve 16 and support flange 12. Rotor 18 and rotorshaft 82 revolve with respect to stator assembly 20 and stator sleeve16. Accordingly, bearing assemblies 23 are provided for this rotationalmovement. Operation of electric motors is well known in the art of thepresent invention, and thus a detailed description of such operationwill be omitted.

Referring to FIG. 5, a top view of a spindle motor assembly of hard discdrive assembly 26 is shown. It should be understood, that many detailshave been omitted from FIG. 5 to more particularly describe a top viewof support flange 12.

Referring to FIG. 5 in conjunction with FIG. 4, support flange 12 is atwo sided PCB. Reinforced or unreinforced thermoplastic may be used forconstruction of support flange 12. Support flange 12 includes PCB traces25 and solder pads 27. Solder pads 27 are provided for connecting statorwires 24 to pads 27. Solder pads 27 are disposed on an upper surface offlange 12. Wires 24 are typically connected to solder pads 27. Solderpads 27 are electrically connected to traces 25 by conductors 40 (e.g.,vias, or leads; the term via means a plated-through hole). Traces 25 areelectrically connected to button contacts 44. Thus, in the preferredembodiment of the present invention, specific orientation is providedfor electrical interface of stator wires 24 to pads 27 on the topside offlange 12, while non-specific (360 degree) orientation is provided onthe underside of flange 12 with exposed traces 25 for electricalinterface with button contacts 44.

In the preferred embodiment of the present invention, four buttoncontacts 44 correspond to four traces 25 on support flange 12 for athree phase spindle motor. However, it should be understood that thenumber of contacts and traces will depend on the number of phases asprovided with a stator assembly and the type of grounding employed ornot employed. In accordance with the present invention, fewer or morecontacts and traces may be used, depending on the number of phases ofthe motor and the type of grounding employed or not employed. Thepresent invention is useful with motors having one or more phases.Additionally, one or more connectors may be used.

As is known in the art of PCBs, film 29 may be deposited for protectionand isolation of traces 25. Also, inner and outer diameters of flange 12may include a coating 73 (e.g., with the same material as used fortraces 25) to limit contamination. Coating 73 is a deposited "trim"around inner and outer diameter edges of flange 12.

Solder pads 27 are located outside stator laminations, as shown in FIG.5. This is to allow easy access for soldering of stator wires 24 to pads27. In this manner, soldering may be done either manually orautomatically. Also, conductors 40 are vias in the preferred embodiment.

In order to understand a more generalized case in accordance with thepresent invention, it should be noted that any of a variety ofconnectors may be disposed in base 15 (shown in FIG. 4). For example,rather than button contacts, spring contacts or compliant pin contactsmay be used. Such connectors may also include non-compliant connectors.Moveover, the shape of connector 43P (shown in FIG. 5) may be varied.

Referring to FIG. 22, an enlarged view of a cylindrical connector 43P inaccordance with the preferred embodiment of the present invention isshown. Connector 43P has a cylindrical shape 255 and a rounded topsection 251. Additionally, lip 254 may be used to seal a drive volumewith insertion of connector 43P to base 15 (shown in FIG. 21). FIG. 21shows a cross-section of assembly of flange-to-connector-to-base inaccordance with the present invention. An interference fit may beemployed for mating connector 43P to base 15 for sealing drive volume 19(shown in FIG. 4). Compression fastener 253 may be employed for holdingconnector 43P. Optionally, adhesive may be used instead of or inaddition to compression fastener 253. FIG. 20 is a bottom view of theflange 12 in accordance with the present invention. As shown, exposedtraces 25 on bottom surface 41 of flange 12 are provided fornon-specific orientation.

First Alternate Embodiment

Referring to FIG. 6, a cross-section of an alternate embodiment of harddisc drive volume 19 is shown. As shown, support ledge 72 is providedwith sleeve 16 for maintaining stator assembly 20 in place. As shown,support flange 12 comprises solder pads 27 for connecting to statorwires 24.

An elastomeric connector element 75 for connector 43P may be usedinstead of button contacts 44 (shown in FIG. 4). Elastomeric connectorelement 75 is disposed in dielectric sheathing material 31 mounted indrive base 15. Such elastomeric connectors are provided by ElastomericTechnologies, Inc., of Hatboro, Pa.

Referring to FIG. 7, a layered-type elastomeric element 210 of the priorart is shown. Elastomeric element 210 includes: support/insulation layer213 (typically made of solid or foam silicone), alternating conductivelayers 211, and alternating non-conductive layers 212.

Referring again to FIG. 6 with continuing reference to FIG. 7,conductive layers 211 are in electrical contact with exposed traces 25.Exposed traces 25 are connected to pads 27 through conductors 40.Elastomeric connector element 75 may be potted to isolate it to mitigateagainst contamination in volume 19. Also, to maintain a sealed drivevolume 19, seal 30 is provided.

Distance 33 between bottom region 34 of rotor 18 to region 35 of drivebase 15 is approximately 1.836 mm.; thickness 34 of driver PCB 11 isapproximately 0.8128 mm.; and thickness 32 of support flanges 12 isapproximately 0.635 mm.

Second Alternate Embodiment

Referring to FIG. 8, a cross section of a portion of drive volume 19 isshown. Support flange assembly 42 may be a molded part having circuitsplated and etched, or a plated pattern, thereon, or an overmolded parthaving circuits embedded therein. An overmolded or molded part may bemade of a thermoplastic resin or other plastic material. Tolerance ring10 is used to provide friction retention for holding stator assembly 20in place. Thus, friction retention locations 36 and 37, namely, theouter and inner surfaces, respectively, of flange wall 28 are forholding stator assembly 20 in place. Flange wall 28 may be notched forexpanding with pressure from tolerance ring 10.

By molding or overmolding support flange assembly 42, tighterdimensional tolerances may be achieved. Also, in an overmolded supportflange assembly 42, circuit portions are part of the structure of harddisc drive assembly 26.

As mentioned above, assembly 42 may be plated with conductive materialand subsequently etched, or, alternatively, may be plated with a desiredpattern. The pattern may comprise traces on both upper surface 77 andlower surface 76 of assembly 42. Conductors 40 are for electricallyconducting through the thickness of assembly 42.

Referring to FIG. 9, a top view of a spindle motor assembly of hard discdrive assembly 26 is shown. Referring to FIG. 8 in combination with FIG.9, four wire button contacts 44 disposed in molded plastic connectorhousing 78 are aligned with traces 25 on assembly 42 and contacts 79 ondriver PCB 11. As shown, connector 43 may be sealed into driver base 15,typically made of aluminum. Additionally, an optional screw may be addedto location 46 for mounting of driver PCB 11 to base 15 to improveelectrical contact between traces 25 and button contacts 44. Statorassembly 20 and magnetic assembly 17 may be raised inside the motorenvelope created by rotor 18 to provide additional space. (Notably,connector 43 is distinct from connector 43P. Connector 43P iscylindrical, whereas connector 43 is rectangular.)

Distance 38 between bottom region 39 of top bearing assembly 80 andbottom region 41 of assembly 42 is approximately 6.95 mm.; connectorheight 45 is approximately 3.378 mm.; and connector width 47 isapproximately 4.05 mm.

Traces 25 are provided with solder pads 27. Vias 48 extend to traces 25on bottom surface 41 of assembly 42. This allows for electricalconduction through the thickness of assembly 42. Additionally, as shownin cut-a-way, traces 25 are circular. Traces 25 may be copperflash-plated with tin or gold. Four traces 25 are for alignment withfour wire button contacts 44 of connector 43. Traces 25 are alsoexposed, which allows molded support flange assembly 42 to be orientedanywhere within a 360 degree axial rotation. This significantlysimplifies alignment during assembly, as the circular circuit patternprovided allows spindle motor assembly 92 to be installed to base 15without need to specifically orient the former relative to a position ofconnector 43.

Stator windings are terminated with stator wires 24 to solder pads 27 ontop surface 77 of assembly 42. Each phase of stator assembly 20 may beconnected to a corresponding circular trace 25 of assembly 42 by via 48.In the preferred embodiment of the present invention, three of thetraces are employed for each phase of a three phase motor, and a fourthtrace is for a common ground. However, a motor with any number of phasesmay be used when practicing the present invention.

Stator assembly 20 may be oriented relative to solder pads 27. By usingvias 48 and traces 25, solder pads 27 may extend outside of statorassembly 20 for accessibility to manual or automated soldering tooling.Wall 28 of assembly 42 may be compressed between tolerance ring 10 andstator assembly 20. Inside diameter 52 of assembly 42 may be press fitover stator sleeve 16 from below. Notches 83 may be provided in flangewall 28 for press fitting to stator sleeve 16.

Typical dimensions of connector 43 include distance 50, between buttoncontacts 44, of approximately 1.77 mm., and distance 49, between pairsof button contacts 44, of approximately 1.27 mm. Typical connector width51 is approximately 4.19 mm.

Specific, Less Specific and Non-Specific Orientations of the Flange tothe Stator Assembly and/or the Connector

Referring to FIG. 10, exposed traces 25 on bottom surface 41 or topsurface 77 of flanges 12 and 42 are illustratively shown. Additionally,it should be understood that a PCC 53 may be made to include traces forless specific or non-specific orientation. As indicated, traces 25 maycomprise as many traces as desired depending on the number of phases andgrounding scheme employed in operation of a spindle motor assembly.Exposed traces 25 allow orientation anywhere within a 360° rotation.This allows for non-specific orientation to a stator assembly and/or aconnector.

Alternatively, traces 25 may shaped as arcuate segments such as traces81 for less specific orientation. Arcuate-segment-shaped traces 81 arefor providing connector contact within a predetermined angular range,but at orientations outside such a range, electrical contact cannot beprovided.

Therefore, it should be understood that traces may be disposed on a topsurface, a bottom surface, or top and bottom surfaces of a supportflange in accordance with the present invention for less specific and/ornon-specific orientations. Traces may be omitted in part or whole forpartially or wholly specifically orienting: stator wires to a topsurface of a support flange, and/or connector contacts to a bottomsurface of the support flange. Solder pads 27 may be provided forspecific orientation. Thus, the present invention provides a variety ofoptions for orientation of a spindle motor assembly to a connector.

Third Alternate Embodiment

Referring to FIG. 11, a cross-section of hard disc drive volume 19 isshown. PCC 53 is coupled to support flange 82. PCC 53 may be bonded toone or both sides of support flange 82.

Referring to FIG. 12 with continuing reference to FIG. 11, a top view ofPCC 53 is shown. As shown, PCC 53 comprises a substrate 55, traces 25,solder pads 27, and connector interface pads 54. Solder pads 27 areprovided on PCC 53 for attachment of stator wires 24. Dash line 83denotes a fold line for PCC 53 corresponding to location 84. PCC 53 maybe bonded to carrier ring 60 and located on top surface 85 of supportflange 82. PCC 53 has a curved contour 87 for conforming about statorsleeve 16.

Connector interface pads 54 are shown with the contact surface side up.Therefore, when PCC 53 is bent around support flange 82 at location 84,connector interface pads 54 are aligned with button contacts 44. This isfor providing electrical continuity between stator assembly 20 anddriver PCB 11. While connector interface pads 54 have been shown in aseries pattern, it should be understood that they may be staggered orotherwise modified for mating with button contacts 44. PCC 53 is bentaround flange 82 such that solder pads 27 remain on surface 85 of flange82, and that connector interface pads 54 are located on surface 86 ofsupport flange 82.

However, PCC 53 need not be bent around support flange 82. Rather PCC 53may be disposed on one side of support flange 82 for mating with a PCBdisposed on the other side of support flange 82. Thus, PCC 53 may befolded or not folded. Also, PCC 53 may comprise exposed traces 25 forless specific or non-specific orientation as previously described hereinwith reference to FIG. 10.

Alternative Mountings

Referring to FIGS. 11 and 13-19, a plurality of alternative means forconnecting spindle motor assembly 92 to drive base 15 are described.

In FIG. 11, laser weld 60 may be employed for holding a spindle motor toa base. However, for laser welding, it is preferred that base 15 andsleeve 16 be made of similar materials. Alternatively, ring 99 of amaterial similar to sleeve 16 may be cast in base 15. Presently, assleeve 16 is made of steel, and base 15 is made of an aluminum alloy,ring 99 is made of steel.

Referring to FIGS. 13 and 14, threads 62 and 63 may be provided to drivebase 15 and rotating shaft spindle motor assembly 92 for attachment byscrewing assembly 92 to drive base 15. Alternatively, a nut 64 havingthreads 93 may be used for mating with threads 63 of assembly 92.Electrical connection is made as assembly 92 support flange 90 bottomside 91 compresses button contacts 44 on connector 43 with the screwingof assembly 92 to base 15 or nut 64. Thus, assembly 92 may be removedfrom base 15 without removing disc 61 from assembly 92.

In FIG. 15, a tolerance ring 65 is used for connecting drive base 15 tospindle motor assembly 92 with friction contact.

In FIG. 16, springlock washer 66 is inserted into notch 94 of statorsleeve 16 for holding drive base 15 to spindle motor assembly 92. Alsoshown is an alternative method of locking button contacts 44 to driverPCB 11. As shown, threaded recess 67 is provided for mating with screw68 for securing driver PCB 11 to connector 43.

Referring to FIG. 17, a heat shrink clamp 69 may be employed to securespindle motor assembly 92 to drive base 15.

In FIG. 18, a bayonet retainer 70 is positioned in notch 95 of drivebase 15 for holding spindle motor assembly 92 secure to base 15.

Referring to FIG. 19, "C"-clip retainer 71 is employed at ledge 96 ofstator sleeve 16 for securing drive base 15 to spindle motor assembly92.

Alternative Flange Assemblies

Referring to FIG. 13, modified support flange 90 is shown. Supportflange 90 may have a sloped edge 302 for clearance for operation ofrotor 18. Alternatively, diameter of support flange 90 may be reducedsuch that edge 301 is within an inside diameter of rotor 18, so as notto interfere with operation of rotor 18.

Referring to FIGS. 23 and 24, flange 12 may be biased at angle 209 withrespect to sleeve 16. When mated with connector 43, flange 12 conformsto the mating surface of connector 43. Biasing flange 12 increases thereliability of electrical contact. The spring rate of flange 12 may bedesigned to be satisfactory in the existing ambient environment, takinginto account shock and vibration. The spring rate of flange 12 dependson stiffness (thickness) and bias angle 209 of flange 12, as well as onthe mass of the parts. It should be understood that the spring rate offlange 12 is designed to be great enough to maintain contact, while notso great as to cause significant deformation of the parts.

Working Model

A working model of a rotating shaft spindle motor and PCB flange inaccordance with the preferred embodiment was constructed in accordancewith the principles of the present invention. The tolerances on endturns of the working model were greatly relaxed as compared with priorart rotating shaft spindle motors. The electrical interface connectionsof the working model do not interfere with motor operation. Thesefeatures and advantages, taken with a non-specific orientation of themotor-to-connector (the connector being disposed in the base),substantially simplified assembly of the working model.

The present invention has been particularly shown and described withrespect to certain preferred embodiments and features thereof. However,it should be readily apparent to those of ordinary skill in the art thatvarious changes and modifications in form and detail may be made withoutdeparting from the spirit and scope of the inventions as set forth inthe appended claims. The inventions illustratively disclosed herein maybe practiced without any element which is not specifically disclosedherein.

We claim:
 1. In a hard disc drive assembly including a base, a spindlemotor, and a driver board, the spindle motor including a rotor, astator, and a stator sleeve, the stator including coupling wires, anapparatus comprising:a support flange located below the stator, thesupport flange being bonded to an outer diameter of the stator sleeve;the support flange including a circuit, the coupling wires for matingwith solder pads on the support flange, the solder pads being inelectrical continuity with traces of the circuit; and a connector havingcontacting elements for electrical continuity mating with the traces ofthe circuit and with the driver board, the connector being disposed inand through the base; the contacting elements of the connector being putinto electrical continuity with the traces of the circuit by mechanicalmounting of the spindle motor to the base; the support flange beingconnected to the stator sleeve at a predetermined bias angle, the biasangle being other than ninety degrees to an axis of rotation of thespindle motor.